Apparatus for forming ring-shaped fasteners from flat stock



May 15, 1956 1.. B. GREEN 2,745,121

APPARATUS FOR FORMING RING-SHAPED FASTENERS FROM FLAT STOCK OriginalFiled Jan. 11, 1951 7 Sheets-Sheet l INVEN TOR. 56 5. 625m Arm/2w May15, 1956 B. GREEN 2,745,121

APPARATUS FOR FORMING RING-SHAPED FASTENERS FROM FLAT STOCK OriginalFiled Jan. 11, 1951 7 Sheets-Sheet 2 56' Q, I "72H 75 519 u 65 45 35 7/70 29 a I 62 27 46 17 66 12 5 '"H In "H" H I" i Q 42 /6. 3 INVENTOR.

[E5 5- pss/v L. B. GREEN May 15, 1956 APPARATUS FOR FORMING RING-SHAPEDFASTENERS FROM FLAT STOCK Original Filed Jan. 11, 1951 7 Sheets-Sheet 5May 15, 1956 a. GREEN 2,745,121

APPARATUS FOR FORMING RING-SHAPED FASTENERS FROM FLAT STOCK OriginalFiled Jan. 11, 1951 7 Sheets-Sheet 4 INVENTOR. 15s 5. fixes/v ArraeA/EysMay 15, 1956 1.. B. GREEN 2,745,121

APPARATUS FOR FORMING RING-SHAPED FASTENERS FROM FLAT STOCK OriginalFiled Jan. 11, 1951 7 Sheets-Sheet 5 47 l 'gl' L. B. GREEN May 15, 1956APPARATUS FOR FORMING RING-SHAPED FASTENERS FROM FLAT STOCK 7Sheets-Sheet 6 Original Filed Jan. 11 1951 INVENTOR. LEE 5. GAEEN 4rNEYS 7 Sheets-Sheet '7 INVENTOR. 55 6. 6/959/ Arroezvsys L. B. GREENSHAPED FASTENERS FROM FLAT STOCK May 15, 1956 APPARATUS FOR FORMING RINGOriginal Filed Jan. 11

United States Patent APPARATUS FOR FORMING RING-SHAPED FASTENERS FROMFLAT STOCK Lee B. Green,.Lakew00d, Ohio Original application January 11,1951, Serial'No. 205,573. Divided and this application January 21, 1953,Serial No.332,382

22 Claims. (Cl. Ill-28) This invention relates to the manufacture ofpronged fasteners of the ring type adapted to be used between and driveninto two wood or other penetrable members to be connected, and relatesmore particularly to improved apparatus for producing such pronged ringfasteners rapidly and economically from sheet metal stock.

This application is a division of original application SerialNo.205,573, filed January 11, 1951.

Anvobject of the present invention is to providenovel apparatus for theproduction of such pronged ring fasteners in which substantially flatpronged fastener blanks are severed in succession from the leading endof a strip of sheetv metal stock and are progressively bent to ringshape to form the completed fasteners.

Another object is to provide novel apparatus-for the purpose mentionedin which the pronged fastener blanks severed from the sheet metal stripare maintained in a series relation with the prongs of each blank ininterfitting or meshed engagement with the prongs of an adjacent blankso as to constitute a strip of blanks and in which the strip of blanksthus produced is curved transversely to convert the blanks into prongedring fasteners.

A further object is to provide such novel apparatus in which the stripof pronged fastener blanks is advanced at substantially the rate ofproduction of the blanks and is progressively curved transversely by aninwardly and longitudinally acting wedging bending force applied toopposite longitudinal edge portions of the strip of blanks to convertthe latter into a tube from the leadingend of which the completedring-fasteners can be disengaged individually or in groups.

Still another object is to provide. novel apparatus of the charactermentioned in which the strip of pronged blanks is subjected to aprogressive transverse bending in a longitudinally tapered or convergingreciprocating hollow'die member by which the blanks of the strip arecurved tothe substantially annularly closed ring shape of the completedfasteners.

Yet another object is to provide novel apparatus for the purposementioned in which the bending of the strip of blanks. transverselythereof is carried out between cooperating relatively reciprocablecoaxial inner and outer die members.

This invention also provides such a novel apparatus in which the stripof fastener blanks is advanced intermittently and is held. againstbackward movementduring the-rest intervals between the intermittentforward movements, and in which the progressive curving of the. stripof. blanks to the substantially annularly closed shape of the completedfasteners is produced by bending forces applied to the strip bythe'hollow die member during such rest intervals.

Aaanother object this invention provides novel apparatus'of thecharacter just mentioned in which the cooperating relativelyreciprocable coaxial inner and outer die membersare convergently taperedin the direction of strip travel and' define a" die passage therebetweenhaving a p or mandrel of the curving die mechanism and showingrelatively wide inlet opening adapted to receive the strip of blanks anda substantially annularly closed outlet opening from which the completedpronged ringfasteners are discharged.

Still another object is to provide novel apparatus of the kind referredto in which the tapered inner or convex die member is a stationarymandrel about which the strip of blanks is bent by bending forcesimparted thereto by reciprocation of the outer or concave diemember,.and in which the mandrel has a stem extension projecting fromthe outer die member and adapted to support the tube of completedpronged ring fasteners being deliveredi The present invention furtherprovides novel apparatus for producing pronged ring fasteners in whichcooperating toothed or serrated shearing die members severthe successivepronged fastener blanks from the strip. of stock and in which certain ofthe die members have projections thereon adapted to deflect the ends ofthe prongs outof the plane of the blank such that when the blank is-bentto closed ring shape the deflected ends of the prongs will incline awayfrom the axis of the'fastener.

As an additional object this invention provides novel apparatus of thecharacter mentioned in which the taper of the cooperating coaxial diemembers is relatively long and bears a relation to the deflection oftheprongends and to the thickness of the stock from which the fastenerblanks are formed, such that the prongs of adjacent blanks of the-stripof blanks will remain inmeshcd relation during the progressive bendingof the strip of blanks to complete the-ring shape of the fasteners. 1

Yet another object is to provide novel apparatus for making pronged ringfasteners in which the major portion of the transverse curving of thestrip of blanksis accomplished between the'inner mandrel die member andthe reciprocably movable hollow outer die member, and-in which a furtherbending of the blanks to a substantially closed ring form isaccomplished by apair of cooperating die rolls connected with the outerdie member for translatory movement therewith.

The invention can be further briefly summarizedasconsisting in certainnovel combinations and arrangementsof parts, hereinafter described andparticularly set out inthe claims hereof.

In the accompanying sheets of drawings:

Fig. 1 is a plan view showing improved-apparatus for the production ofpronged fasteners of the ring type'in accordance with. the presentinvention, the apparatus being viewed in plan substantially asindicated-by line 1--1 of Fig- 2; a

Fig. 2 is a longitudinal vertical section taken through the apparatus onthe irregular section line22 of-Fig. 1;

Fig. 3 is a longitudinal vertical section corresponding with the portionof Fig. 2 which illustrates the-cooperating punch and stake die' membersof the shearing. die mechanism, but showing such die members on a largerscale and in an open position;

Fig. 4 is a longitudinal vertical section similar to that of Fig. 3 butshowing the cooperatingpunch-and stake die members in closed position;-

Fig. 5 is a longitudinal vertical section corresponding with the portionof Fig. 2 which illustrates the-curving die mechanism. for curving thestrip of blanks, but showing such curving die mechanism on a largerscale;

Fig. 6 is a partial transverse section showing thejreceiving end of thecurving die mechanism, the View being taken substantially as indicatedby line 6-6 of Fig. 5;

Figs. 7, 8 and 9 are transverse sections taken through the curving diemechanism substantially as indicated by section lines 77, 88 and 99,respectively, of Fig. 5;

Fig. 10 is a perspective view of the inner die member such inner 'die indetached relation;

Fig. 11 is a plan view of the strip of fastener blanks showing theprogressive change in the shape of this strip from flat to tubularshape;

Fig. 12 is a side elevation of a completed pronged ring fastener of thekind produced by the method and apparatus of the present invention;

Fig. 13 is an end view of the completed fastener;

Fig. 14 is a plan view of a fiat or developed pronged fastener blankshowing the same as produced by the shearing die mechanism and prior tobeing curved to ring shape;

through the shearing die mechanism substantially as indicated by sectionline 17-17 of Fig. 18;

Figs. 18 and 19 are partial longitudinal sectional views taken throughthe shearing die mechanism at laterally spaced points, as indicated bysection lines 1818 and 19--19, respectively, of Fig. 17;

Fig; 20 is a partial transverse sectional view taken through theshearing die mechanism substantially as indicated by line 20-20 of Fig.19;

Fig. 21 is a fragmentary horizontal view of the lower stripper of theshearing die mechanism, the view being taken substantially as indicatedby line 2121 of Fig. 20;

Fig. 22 is an exploded view in perspective showing "the component partsof the curving die mechanism; and

Fig. 23 is a plan view showing a modified form of the curving diemechanism.

This novel apparatus for producing pronged ring fasteners comprises, ingeneral, a shearing die mechanism by which pronged fastener blanks 11 ina substantially fiat or developed form are severed in succession fromthe leading end of a strip of sheet metal stock 12 and a curving diemechanism 13 by which the pronged fastener blanks are curved to asubstantially closed annular shape to thereby convert the blanks intopronged ring fasteners 14. The novel apparatus also includes a feedmechanism for advancing the strip of stock 12 to the shearing diemechanism 10 and which also supplies the forward motion for advancingthe fastener blanks through the curving die mechanism 13. Additionally,the novel apparatus includes punch press mechanism 17 for actuating theshearing die mechanism 10 and lever mechanism 18 for actuating thecurving die mechanism 13.

Before proceeding with the more detailed description of the apparatus,it is appropriate at this point to describe the pronged ring fastener 14and the pronged fastener blank 11 from which the completed fastener isformed. As shown in Figs. 12 and 13 the fastener 14 is a ring-shapedsheet metal member having oppositely extending annular groups ofsubstantially triangular prongs 19 and adapted to be driven into twobodies, of wood -or other penetrable material, between which thefastener is disposed and which are to be connected by such fastener.

The pronged ring fastener 14 is more fully disclosed and is claimed incopending patent application Serial No. 74,776, filed February 5, 1949,and now Patent No. 2,558,131, granted June 26, 1951. As to the manner ofusing the fastener 14, it is sufiicient for the purposes of the presentapplication to explain that when the fastener is disposed between a pairof wood members and the annular groups of prongs 19 and 20 are forcedinto such wood members these prongs become deflected outwardly orclinched as they imbed themselves in the wood members, thus enabling thefastener to form a rigid and durable connection for holding such woodmembers firmly together.

As shown in Figs. 12 and 13, the prongs constituting the annular groupsof prongs 19 and 20 are disposed in circumferentially offset orstaggered relation such that the substantially triangular notches 21formed between each pair of prongs 19 will be located in axial alignmentwith the prongs 20 of the opposite group and, similarly, thesubstantially triangular notches 22 formed between the pairs of adjacentprongs 20 will be located in axial alignment with the prongs 19. Theprongs 19 and 20 are of such proportions that they will readily enterthe wood members when the fastener is subjected to an appropriatedriving force.

To facilitate the outward deflection or clinching of the prongs 2t) and21 as they are forced into the wood members, the free end portions ortops 19a and 20a are initially deflected outwardly so as to stand in anobtuse angle relation to the axis of the fastener. To enable thefastener 14 to draw the wood members tightly together, the notches 21and 22 are of such depth that their apices will lie on or adjacent acircumferential median line 23.

The completed pronged ring fasteners 14 are formed from thesubstantially fiat pronged fastener blanks 11 which have been sheared insuccession from the leading end of the strip of sheet metal stock 12. Asshown in Figs. 14, 15 and 16, the fastener blanks 11 have oppositelyextending rows of the prongs 19 and 20 thereon with the interveningnotches 21 and 22 between the pairs of adjacent prongs. The prong end19a and 20a of the prongs 19 and 21) have been deflected downwardly outof the plane of the blank such that when the blank is curved to annularshape these prong ends will stand in the above-mentioned outwardlydeflected obtuse angle relation to the axis of the fastener.

It will be seen from Figs. 14 and 16, and from various other views ofthe drawings, that one of the prong edged fastener blanks 11 is severedfrom the leading end of the stock strip 12 by each shearing operation.It will also be seen that during each shearing operation, a transverselyextending row of the V-shaped notches 21 is cut in the stock strip andthat the V-shaped segments thus sheared out of these notches of thestock strip form the rear row of prongs 20 of the blank. In this novelmethod, the row of notches 21 being cut by the shearing operation islocated at a point on the stock strip which is in such close relation tothe previously cut row of these notches remaining on the extreme leadingend of the strip, that the oppositely extending V-shaped prongs 19 and20 will have their bases located substantially on the median line 23 ofthe blank being produced.

When the fastener blanks 11 are sheared from the leading end of thestock strip 12 they are completely severed from the stock strip butremain in the relation shown in Fig. 16 in which the prongs 20 of therear edge of one fastener blank are in meshing engagement with theprongs 19 of the forward edge of the next succeeding fastener blank.When the flat fastener blanks 11 are in this inter-engaged or meshedrelation they constitute a so-called strip of blanks 12a to whichfurther reference will be made hereinafter.

As shown in Figs. 3 and 4, the shearing die mechanism 10 includes a pairof upper and lower carrier plates 25 and 26 of which the lower carrierplate 26 is a stationary member and the upper carrier plate member 25 isreciprocably movable relative to the lower carrier plate. The shearingdie mechanism 10 also includes an upper or punch shearing die member 27and a lower or stake shearing die member 28. Additionally, this shearingdie mechanism includes upper and lower stripper die members 29 and 30.

The upper and lower shearing die members 27 and 28 have groups of teethor serrations27a and 28a thereon extending toward each other but withthe teethofthese groups laterally offset a distance such that the teeth27a of the punch 27 will be caplble of moving downwardly between theteeth 28a of the stake die member 28. The teeth 27a of the punch 27 andthe teeth 28a of the stake 28 correspond in plan size, and shaperespectively with the prongs and 19 of the fastener blanks 11. Duringeach such downward movement of the punch 27in shearing relation to thestake 28, the teeth 27a of'the punch will shear the stock strip 12transversely thereof along a zig-zag line corresponding with the toothprofile of the fastener blank and thereby shear one of the fastenerblanks 11 from the leading end of the stock strip.

The punch and stake die members 27 and 28 are here shown as embodying anovel construction in that these die members are composed of groups ofblades 31 and 32 disposed in vertically edgewise relation with theblades of each group in face-to-face engagement. The teeth 27a and 28aconstituting the shearing elements of these die members are formedby thetapered upright end edges of these grouped blades. When the die members27 and 28 are composed of such groups of component blades they can bemore economically constructed and maintained in a sharp conditionbecause the tapered end edges constituting the shearing teeth can bemore readilyand accurately formed on individual blades by appropriatemachining or grinding operations than they could be on a solid dieblock.

The blades 31 constituting the punch 27 can be mounted on'the carrierplate in the above-described grouped relation by the use of clampingblocks 33 and 34 (see Figs. 3 and 4) between which the blades aredisposed and which clamping blocks are connected with the carrier plateby suitable screws 35 and 36. The clamping blocks'33 and 34 have theadjacent faces 33a and 34a thereof disposed in oppositely inclinedrelation so as to define therebetween a dovetail-shaped space or recessin which the dovetail-shaped upper portions of the blades 31 engage.

The clamping block 34 has limited shifting movement relative to theclamping block 33 for lockingor releasing the blades 31. Such shiftingof the clamping block 34 toward the clamping block 33 is produced byactuating screws 38 extending through a backing block 39 which is alsomounted on the carrier plate 25. After the, clamp.- ing block 34 hasbeen shifted by the actuating screws 38 toward the clamping block 33 togrip the dovetailportions of the blades 31 therebetween, theconnecting-screws 36 are tightened to maintain the clamping block 34 inthis relation.

The group of blades 32 of the lower or stake shearing die member 28 aremounted on the lower carrier plate 26 in. a similar manner by theprovision of a pair of: clamping blocks 40 and 41 and a backing block42.

The strippers 29 and 30 are upper and lower die members which are in theform of movable blocks located adjacent the clamping blocks 34 and 41and-which cooperate, respectively, with the shearing die members 28 and27. The upper stripper 29 has a row of teeth or serrations 29a formed onthe front edge thereof and which are in meshing engagement with. theteeth 27a of the punch 27. Similarly, the lower stripper 30 is' providedwith a row of teeth 30a on the upright rear edge thereof which are inmeshing engagement with the teeth 28a of the stake 28. The upperstripper 29 is engageable; with the upper surface of the stock strip 12for applying pressure thereto, as shown in Fig. 4, and the lowerstripper 30 is engageable with the lower surface of. the rear endportion of thestrip 12a of fastener blanks and with the lower surface ofthe extreme front endportion of the stock strip 12, as shown in Fig. 3.

The upper stripper 29 is movable toward and away from the clamping block.34 during the closing and openingmovements of the punch 27 and theoutward or down.-

ward movement of this stripper away from theclamping block 34; is,produced by compression springs 43 disposed between this stripperand thecarrier plate 25. The lower stripper 30 is movable toward and away fromthe clamping block 41 during the closing and opening movements ofthepunch 27 and the outward or upward movement of this stripper awayfrom the clamping block. 41 isproduced by compression springs 44disposed between this stripper and the lower carrier plate 26.

The lower stripper 30 forms a yieldable support for 'the end portionofthe stock strip 12 which overlies the teeth 28:: of the stake 28, asshown in Fig. 3, andwhich overlying portion is about to be severed'fromthe stock strip by'the punch 27. When this overlying portion is severedfrom the stock strip it forms a fastener blank 11 which isgrippedbetween the stripper 30 and the punch 27 and is carried downward by thepunchin the completion of the shearing action performed by the latter.When the punch 27 is moved upwardly by the carrier plate 25 followingthis shearing operation, the fastener blank 11 just produced is liftedby the lowerstripper 30 to a position in meshed alignment with thepreviously severed fastener blanks.

Another important feature of the shearing die mechanism 10 is thatthepunch 27 and the upper stripper 29 are providedwith rows of dependingprojections or lugs 46 and 47 which are carried by the teeth 27a and29a, respectively, and act on the stock strip 12 during the shearingoperation to deflect downwardly the. end portions 19a and 20a of theteeth 19 and 20 of the fastener blank 11 being formed. The lugs46 and 47are located at the ends of1the teeth 27a and 29a and are formed asintegral depending extensions of these teeth. To permit such downwarddeflection of the ends of the prongs of the fastener blank being formed,the end portions of the teeth 28a and 30a of the stake 28 and the lowerstripper 30 are beveled downwardly, as is best shown in Figs. 18 and 19,and" these bevels are indicated by the reference characters 48 and 49.

During the closing movement of the die mechanism 10, the depending lugs46 and 47 of the punch 27 and the upper stripper 29 engage the uppersurface of the stock strip 12 ahead of other portions of these diemembers andthe depending lugs 46 start the shearing operation by whichthe next fastener blank 11 will be sheared from the leading end of thestock strip. The continued downward closing movement of the punch 27causes, the teeth 27a thereof to complete the shearing of the prongs 20from the stock strip 12. During this sh'earingoperation the lugs 46cooperate with the beveled portions 49 of the lower stripper 30 todeflect theends 20a ofthe prongs 20 downwardly. Also during thisshearing op.- eration the lugs 47' of the upper stripper 29 cooperatewith the beveled portions 48 of the stake 28 to deflect the ends 1911 ofthe prongs 19 downwardly.

The shearing of a fastener blank 11 from theeleadiug end of the stockstrip 12 leaves on the stock grip a'row of prongs 19 for the nextsucceeding blank to be sheared from the stock strip. The row of prongs19 thusformed on the leading end of the stock strip 12 will becompletely formed prongs having the downwardly deflected ends 19a suchthat when the next fastener blank 11 is sheared from such leading end ofthe stock strip it will only be necessary for the shearing operationtoform the prongs 20 and the downwardly deflected ends 20a. Thus eachclosing of the die mechanism 10 willresult in a completely formedfastener blank 11 being severed from the stock strip 12.

During the opening movement of the die mechanism 10 the upper carrierplate 25 is moved upwardly away from the stationary lower carrier plate26 and, during the initial portion of this opening movement, the springs43'maintain the upper stripper 29 stationary for a short interval oftime thereby holding the stock strip 12 clamped against the stake 28until the groups of shear 7 ing teeth 27:: and 28a of the die members 27and 28 have separated from each other. During such opening movement ofthe die mechanism 10, the lower stripper 30 is lifted by the springs 44,thereby elevating the lastsevered fastener blank 11, and also severalpreviously severed adjacent blanks, to a position of axial alignmentwith the strip 12:: of fastener blanks, as shown in Fig. 3.

The opening and closing actuation of the shearing die mechanism isaccomplished by suitable actuating mechanism which is here shown asbeing a conventional punch press 17 (see Figs. 1 and 2) having a bed 51and .a reciprocahlc ram or slide 52. The upper carrier plate is suitablyattached to the lower end of the ram 52 and the lower carrier plate 26is suitably mounted on a table 53 which is in turn carried by a bolsterplate 54 mounted on the bed 51. As is customary in punch presses, theram 52 is actuated in a conventional manner from acrankshaft (not shown)such as to produce the desired reciprocating opening and closingmovements of the upper carrier plate 25 relative to the lower carrierplate 26.

The feed mechanism 15 advances the stock strip 12 to the die mechanism19 with an intermittent forward movement in timed relation to theopening and closing movement of this die mechanism. This feed mechanismis here shown as comprising a pair of cooperating upper and lower feedrolls 5S and 56 which are adapted to grip the stock strip 12. One orboth of the feed rolls 55 and 56 are adapted to be driven by linkageactuated from the crankshaft of the punch press 17.

In this instance the actuating linkage for the feed rolls is shown ascomprising a lever 57 which is drivingly connected with the lower feedroll 56 by means of a ratchet wheel 53 and a pivoted pawl 59. The lever57 is rockable about the axis of the lower roll 56 and carries the pawl59. A thrust link 69 connects the lever 57 with the crankshaft of thepunch press. Swinging movements imparted to the lever 57 cause the lowerfeed roll to be driven with an intermittent forward feeding movement bythe ratchet wheel 58 and the pawl 59 to thereby advance the stock strip12 to the shearing die mechanism 10 with a step-by-step movement.

The stock strip 12 may be supplied from an available source of supplysuch as a roll of this strip material from which the strip is withdrawnby the feed rolls 55 and 56 of the feed mechanism 15. In passign fromthe feed rolls to the shearing die mechanism it the strip 12 issupported on a feed plate 61 and is confined in a longitudinal guidcway62 by the overlapping edge portions 63a of a pair of laterally spacedstrips 63. The strip 12a formed by the intermeshed fastener blanks 11passes to the curving die mechanism 13 by moving through a clampingdevice 65. This clamping device serves to hold the strip of blanksagainst backward movement during the operation of the curving diemechanism 13 and is constructed and operated as a part of the shearingdie mechanism 10.

The clamping device 65 comprises a pair of upper and lower clampingmembers 66 and 67 and a pressure plate 68. These clamping members 66 and67 define therebetween a longitudinal guide passage 69 which is alignedwith the guideway 62 and direct the strip 12a of fastener blanks to thecurving die mechanism 13. The lower clamping member 67 is locatedimmediately adjacent the backing block 42 and is secured to the lowercarrier plate 26.

The upper clamping member 66 is connected with the lower clamping member67 by screwsl'tl which permit a limited movement of this upper clampingmember toward and away from the lower clamping member for clamping orreleasing the strip 12a of fastener blanks. Compression springs 71disposed between the clamping members 66 and 67 act on the upperclamping member to normally urge the same away from the lower clampingmember so as to release the clamping pressure on 8 the strip of blanks.As shown in Figs. 3 and 4 the upper clamping member 66 is provided withan integral lateral extension 66a which projects rearwardly in overlyingrelation to the backing block 42 and a portion of the lower stripper 30.

The pressure plate 68 is connected with the upper carrier plate 25 byscrews '72 which permit relative movement between the pressure plate andthis carrier plate. Compression springs 73 disposed between the uppercarrier plate and the pressure plate 68 act on the latter to normallyurge the same in a downward direction away from the carrier plate.

When the die mechanism 10 is being closed by downward movement of thecarrier plate 25, the pressure plate 68 engages the upper clampingmember 66 before the punch 27 or the upper stripper 29 engages the stockstrip 12 and applies downward pressure to this upper clamping member,causing the same to compress the springs 71 nad clamp the strip 12a ofblanks against the lower clamping member 67. Such downward movement ofthe upper clamping member 66 also causes the extension portion 66athereof to cooperate with the backing block 42 and the stripper 30 toapply clamping pressure to the portions of the strip 120 which arelocated in overlying relation to this backing block and stripper.

While this clamping pressure is maintained on the strip 120 of fastenerblanks by the upper clamping member 66 this strip is held againstbackward movement so as to enable the curving die mechanism 13 to carryout its curving function, as explained hereinafter. The bolding of thestrip of blanks against backward movement by the upper clamping member66 also prevents jamming of the dies 27 and 28 during the shearingoperation such as might otherwise occur if movement or pressure weretransmitted in a backward direction through the previously shearedfastener blanks to these shearing dies or to the leading end of thestock strip 12.

The bottom of the guide passage 62 of the clamping device 65 is formedby the top surfaces of the lower clamping member 67, the backing block42 and the stripper 3t) and during the advance movement of the strip 12aof blanks the individual blanks l1 slide on these top surfaces. Toprevent the downwardly deflected prong ends 19a and 20a of the fastenerblanks from becoming flattened or dulled by the clamping pressure beingapplied by the clamping device 65, a plurality of longitudinal grooves75 of substantially triangular cross-section are formed in the topsurface of the stripper 3d, the backing block 42 and the clamping member67. These grooves accornodate the downwardly deflected ends of theprongs 19 and 29 of the fastener blanks while the blanks are in thepassage 69.

As shown in Figs. 20 and 21, the grooves 75 are disposed in a laterallyspaced relation corresponding with the lateral spacing of the prongs 19and 20 of the fastener blanks 11. The grooves 75 of the stripper 3d, thebacking block 42 and the lower clamping member 67 are in an alignedrelation so as to form continuous channels in which the downwardlydeflected prong ends are longitudinally movable during the advancetravel of the strip of blanks.

The curving die mechanism 13 and its function constitute an importantpart of this invention and will. be described next. As shown in Figs. 2and 5, the curving die mechanism 13 is mounted on the table 53 to theright of and immediately adjacent the shearing die mechanism It) so asto receive the strip 12a of fastener blanks from the latter. The curvingdie mechanism comprises, in general, a longitudinal guidebox '77 and apair of coaxially extending inner and outer curving dies 78 and '79disposed in such guidebox.

The guidebox '77 comprises a channel-shaped bottom member 77a and acover 7717. The channel-shaped bottom member 77a has laterally spacedupright side walls 8t} connected by a transverse bottom Wall 81 suchthat these wallsdefine a longitudinal guideway 82. The side andbottomwalls are'preferably provided with a lining of suitable bearingmaterial 83. The bottom member 7711 is secured to the table 53' as bymeans of the screws 84 which extend into integral depending legs 85provided at the ends of this bottom member and which are held againstthe table by the attaching screws.

The cover 77b is secured to the side walls80 of the bottom member 77a incovering relation to the guideway 82 as by suitable screws 86. The coveris also provided on the underside thereof with strips 87 of suitablebearingmaterial. 'The cover 77b also forms a support for the inner diemember 78 and, for this purpose, is provided with longitudinally spaceddepending abutment lugs. 88a, 88b and 88c against which the inner diemember is held by clamping screws 89.

The inner die member 78 is in the form of a longitudinally extendingconvexly curved mandrel which varies progressively in shape from arelatively wide flat portion 78a at the receiving end of. the curvingdie mechanism 13 to -a substantially circular rod portion 78b at thedelivery end of the curving die mechanism. The longitudinal side edges90 of the flat portion of this inner die are rounded. to a radius ofcurvature corresponding substantially with the radius of curvature ofthe rod portion 78b such that the longitudinally converging taper ofthese rounded side edges will merge smoothly into the rod portion 78b.

The inner die or mandrel 78 preferably has transverse recesses 91 formedin the top surface thereof and spaced apart longitudinally to correspondwith the spacing of the abutment lugs 88 of the cover 77b. When the die78 is.connected with the cover by the screws 89, the abutment lugs 88engage in the recesses 91 such that the abutment lugs hold the diefirmly in place in the guidebox 77 and absorb the longitudinal thrust towhich this die is subjected during the curving operation.

The strip 12a of fastener blanks is delivered into the guidebox 77beneath the wide flat end 78a of the inner die 78, as shown in Figs. and6. For supporting the strip 12a in the guidebox such that this stripwill lie against the bottom surface of the inner die 78, the guidebox isprovided with a-strip support 92 which is here shown as being asubstantially wedge-shape plate member. The strip support 92' extendslongitudinally in the guidebox 77 between the laterally spaced portions83a of the bearing material carried by the bottom wall 81 and is securedto such bottom wall by suitable screws 92a.

The outer die member 79 of the curving die mechanism 13 is a hollow diemember which is'concavely curved internally thereof and embraces theinner die member or mandrel78. As shown in the drawings, this outer diemember 79 comprises a pair of elongated die blocks 79a and 79b havingcomplemental longitudinal grooves 94 and 95 in their adjacent faces. Attheir forward ends the die blocks 79aand 79b have substantially straightportions 93.and the complemental grooves 94 and 95 of these straightportions definea substantially cylindrical passageportion 10% throughwhich the stem or rod portion 78b of the inner die 78 extends.

The die 79 is of such length in relation to the die box 77 that thestraight forward ends 93 of the die blocks 79aand 79b project from theforward end of the die box. Rearwardly of the straight portions 93, thedie blocks 79a and 79b are of a tapered form with respect to theiradjacent faces such that the grooves 94 and 95 thereof extend in alaterally spaced rearwardly diverging relation and embrace the roundedlongitudinal side edges 90 of the tapered portion of the inner die 78.

The die blocks 79a and 7 9b are held in connected relation at theirforward ends by a pair of upper and lower splice plates 96 and 97 whichare secured to the straight portions 93 by screws 98. The rearwardlyextending tapered portions of the die blocks 79a and 79b have taperedspacing blocks 100a, 100b and 100a located there between abovethegrooves 94 and and are held.in con nected relation by screws 101 whichextend throughthese .spacer blocks.

The adjacent ends of the spacer blocks a and100b define a gap 102through which the depending abutment lug 88b of the cover 77b extendsand the adjacent ends of the spacer blocks 1001) and 100C define anothersuch gap 103 through which the depending abutment lug 880 of the coverextends.

It willbe understood that the spacer blocks 100a, 100b and 100a arelocated between the opposed pair of longitudinal clamping faces 104 and1050f the die blocks 79a and 79b and that when thedie blocks are securedtogether by the screws 101 the die blocks and spacers form a rigidassembly constituting the outer die member 79. The lower pair of opposedlongitudinal faces 106 and 107 of the die block 79a-and 79b lie onopposite sides of the strip support 92 as shown in Figs 6 and 7.

When the inner die or. mandrel 78 and the hollow oute die 79 areassembled in the guidebox 77 they occupy the relative positions shown inFigs. 5, 6 and 7, such that the inner and outer die members definetherebetween a longitudinal die passage 109 which varies progressivelyin shape longitudinally of the curving die mechanism from a passageportion 109a having a relatively wide flat bottom at its receiving end(Fig. 6) to a substantially cylindrical passage potrion 10911 at itsdischarge-end (Figs. 8 and 9). This die passage is traversed by thestrip 12a of fastener blanks and during the forward travel of the Vstrip through. this passage, its cross-sectional shape is changedprogressively, as shown in Figs. 10 and 11, from a flat strip into asubstantially cylindrical. tube 110 of completed-ring-shaped fasteners14.

During this progressive change in the shape of the strip 12a of fastenerblanks the longitudinal edge portions of the strip are deflectedupwardly and inwardly. by the concavely curved sides of the die passage109 so as to conform to the transverse curvature and longitudinal taperof the inner die 78. The upward and inward curving of the longitudinaledges of the strip 12a causes this strip to be progressively wrappedaround the inner die and results in these edges ultimately being broughtinto an opposed-or substantially abutting relation, as indicated by-thelongitudinal line 111 of Fig. 11. I

From the construction of the clamping device 65 and the curving diemechanism 13 as thus far described, it will be seen'that the die passage1090f the curving die mechanism is aligned substantially with theguideway 62, such that the die. passage and the portion of theguidewayextending. through the clamping. device 65 define a guidepassage in which the sheetmetal blanks. are movable andare confined in asubstantially co-planar relation with the adjacent edges ofadj'acentblanks-in abutting engage.- ment. The guide passage in whichthe strip of blanks travels is defined between the spaced-apart guidesurfaces of the members 66 and 67 of the clamping device 65 andbetweenthe guide surfaces of the die members forming the curving diemechanism 13. The confinement of the blank in thisguide passage preventsbuckling of the strip of blanks'while such strip is being advanced bythe pushmg force being supplied by the feed mechanism 15 and also whilethe strip of blanks is being curved transversely by the impingements ofthe die member 79 thereagainst.

In accomplishing the upward'and inward curving of the longitudinal edgesof the strip 12a, the outer die '19 is re.- ciprocated in the guidebox77 such that during each work: tng stroke of this outer die it movesrearwardly around and in closing relation to the tapered portion of theinner die 78, causing the divergently tapered transversely curved wallsof the grooves 94 and 95 to impinge the longitudinal edges of the .stripandbend the same around against the curved longitudinal edges of theinner die. These working strokes need be of only a relatively shorttravel, inas+ much as a short. longitudinal movement of the outer die ina rearward. direction will cause a rapid closing of the diverginggrooves'94'and 95 relative to the longitudinal side edges of the taperedflat portion of the inner die 78.

The impingement of the longitudinally divergent transversely curvedwall-s of the hollow outer die 79 against the opposite edge portions ofthe strip by the success1ve rearward strokes of this die, results inwedging impact bending forces being repeatedly applied to such edgeportions externally of the tubular shape into which the strip is beingconverted. These impact bending forces are therefore substantiallyopposed wedgingly inwardly and longitudinally acting impact bendingforces which are very effective in causing the progressive curving ofthe strip to tube form while it is being advanced through the curvingdie mechanism. l The working strokes which produce the closing movementof the outer die 79 relative to the inner die 78 are carried out in suchtimed relation to the functioning of the shearing die mechanism and theclamping device 65 that during the bending of the longitudinal edges ofthe strip 12a around the inner die the strip will be stationa'ry andwill be held against backward movement by the clamping device. Duringthe return or opening movement of the outer die 79 relative to the innerdie 78 and during such time that the outer die is in its open position,the strip 12a is free to be advanced by increments of forward movementapplied to the rear end of this strip by the leading end of the stockstrip 12.

For accomplishing the final portion of the curving of the strip 12a ofblanks into the tube 110, the outer die 79 is preferably provided with apair of cooperating roll 112 and 113 which are located respectively inrecesses of the straight end portions 93 of the die blocks 79a and 79b.The rolls 112 and 113 have annular grooves 114 therein corresponding incurvature with the tubular delivery portion 10917 of the die passagesuch that when the forward end of the strip 12a traverses this deliveryportion, these rolls will squeeze and size the tube 110 by atransversely inwardly acting rolling pressure applied to opposite sidesof the partially closed tube, so as to bring the edges thereof intosubstantially meeting relation along the line 111 and such that thecompleted fasteners 14 will all be of a substantially uniform diameter.The rolls 112 and 113 are rotatably mounted in the splice plates 96 and97 and, for this purpose, are provided with shaft extensions 112a and113a which are journaled in suitable bushings 115 carried by thesesplice plates.

As shown in the drawings, the rod portion 78b of the inner die '78 is ofa length to extend through and project from the tubular delivery portion10% of the die passage and the forwardly projecting portion of this rodconstitutes a support for the tube 110 of completed pronged ringfasteners 14. Since the blanks from which these fasteners have beenshaped are completely severed from each other, it will be seen that thefasteners are maintained in the tubular relation merely by theinter-engagement or meshing of the prongs of adjacent fasteners. Thecompleted fasteners can therefore be readily disengaged from the leadingend of the tube 110, either as individual fasteners or as stacks of suchfasteners. The completed fasteners 14 which have been thus disengagedfrom the leading end of the tube 110 can be suitably packaged for saleeither in a bulk condition or as stacks of fasteners for use in themagazines of various fabricating machines.

Various forms of actuating mechanism can be employed for imparting thereciprocating working and return strokes to the outer die member 79 ofthe curving die mechanism 13. In this instance actuating mechanism 18 isprovided which includes a transverse rockshaft 117 located adjacent theright-hand end of the table 53 and to which rocking movements areimparted by a lever 118. The rockshaft 117 is journaled in a pair oflaterally spaced arms 119 and 120 of a bearing bracket 121 which issecured to the table 53 as by means of the screws 122.

A forked lever 123 mounted on and keyed to the rockshaft 117-between thearms 119 and 120 of the bearing bracket 121 has a P Of upwardlyprojecting laterally spaced lever arms 123a and 123b. Pivot pins 124car- 'Apair of links 125 and 126 connect thearms 123aand 123k with theforward end of the outer. die 79. For this purpose the thrust links 125and 126 are pivoted at one end thereof on the pivot pins 124 and at theopposite end thereof are connected with the outer die 79 by means of apair of pivot pins 127. The pivot pins 127 are here shown as being inthe form of studs mounted in the straight end portions 93, the dieblocks 79a and 79b and projecting laterally outwardly therefrom insubstantially aligned relation.

The actuating mechanism 18 also includes a link 128 connecting the lever118 of the rockshaft 117 with a bellcrank lever 129. The lever 129 iscarried by a shaft 131) which is journaled in a bearing bracket 131mounted on the cover 77b of the guidebox 77. The bellcrank lever 129comprises lever arms 12% and 12%, of which the lever arm 129a ispivotally connected with the link 128. The lever arm 12% carries aroller 132 which engages in the recess 133 of a bracket 134 which iscarried by and reciprocably movable with the ram 52 of the punch press17. When the die member 79 of the curving die mechanism 13 is actuatedby movement transmitted from the ram 52 of the punch press 17 through anarrangement of levers and links such as that just described above, itwill be seen that the strokes of the die member 79 will be produced in adesired timed relation to the actuation of the shearing die mechanism 10and the clamping device 65, as well as in timed relation to theintermittent forward movement provided by the feed device 15 for thestock strip 12 and the strip 12a of fastener blanks.

Before summarizing the detailed operation of the novel apparatus of thisinvention, it should be explained that the sheet metal of the stockstrip 12 can be of any desired thickness or gauge, depending upon thenominal size and requirements of the pronged ring fasteners 14 beingproduced. The longitudinal taper of the inner and outer .dies 78 and 79of the curving die mechanism 13 bears an important relation to thethickness of the sheet metal of the stock strip 12 and to the angularityor extent of deflection of the prong ends 19a and 20a, in that the taperangle of these die members should be of such gradual slope that theprongs of the adjacent fastener blanks 11 of the strip 12:! will remainin the above explained interengaged or meshed relation during thecurving of the strip into the tube 110. It is important that the prongsof the adjacent fastener blanks 11 of the strip 12a remain in suchmeshed relation because the advance movement of all of the fastenerblanks through the curving die mechanism 13 can then be produced bymotion supplied to the rear end of the strip 12a by the leading end ofthe stock strip 12. Y

The production of the pronged ring fasteners 14 by the novel apparatusof this invention has already been explained to a considerable extent inthe foregoing detailed description, such that only a summarization ofthe detailed operation will need be given at this point. The strip 12 ofsheet metal stock is advanced with a step-by step feeding movement bythe feed roll mechanism 15. Fig. 3 shows the leading end of the stripstock 12 in a position overlying the stake die member 28 and the lowerstripper 30 and in readiness for the shearing of the next fastener blank11 therefrom by the punch 27 and the stripper 29. Fig. 4 shows the diemembers of the shearing die mechanism 19 in their closed position inwhich the next fastener blank referred to above has just been shearedfrom the leading end of the stock strip 12.

During the closing of the die mechanism 10, the gripping device 65 isactuated to apply a clamping force to a small number of the fastenerblanks constituting the rear end of the strip 12a. This clamping oftherear end of the strip of blanks in the clamping device 65 holds '13thestrip of blanks against backward movement and prevents the fastenerblanks which have just been sheared from the stock strip 12 from beingpushed against the leading end of the stock stripsuchas mightcausejamming of the shearingdie mechanismduring the shearing of the nextfastener blank from the stock strip.

While the rear end of the strip 124: of fastener blanks is beingclampingly held'against backward movement by the clamping device 65, theram 52 of the punch press 17 continues its downward movement to carryoutthe shearing of the fastener blank from the stock strip 12. Thiscontinued downward movement of the ram 52 causes a counter-clockwiserocking movement to be imparted to the bellcrank lever 129 by thebracket 134. This rockingmovement' of the bellcrank lever 129 applies apulling force through the link 128 which swings the lever 118 towardthe; left, thereby causing the thrust links 125 and 126 to transmit.actuating movement to the outer die 79'of the curving .die mechanism 13.

The resulting movement of the outer die 79 toward the left causes theconcavely curved internal wall'portions of this die member which definethedie passage 109 to impinge againstthe longitudinal side edges of thestrip 12a andcurve such side edges upwardly and inwardly around theinner die 78. The working strokes of the ram 52can be carried out veryrapidly and, with each closing of, the die mechanism to produce anotherone of the fastener blanks 11, the outer die 79 of thecurving diemechanism 13 will be moved through a working stroke to impart a bendingforce to the longitudinal side edges of the strip 12a.

Duringthe opening of the die mechanism 10, the ram 52 moves upwardlythereby rocking the bellcrank lever 129in a clockwise direction andtransmitting motion to the outer die 79in a direction tolretract or openthe same relative to the inner die 78. Theupward movement of the ram 52also releases the clamping force being applied tothe rear end of thestrip of blanks by theclarnping device 65, after. which the feedmechanism is actuated by the link 60 to impart another forwardfeeding'movement to the'stock strip 12. Duringsuch forwardfeedingmovement of the stock strip 12, its forward'end pushes the strip12a of fastener blanks in a forward direction, thereby advancing thisstrip a similar distance into the. curving die mechanism 13.

As the'result of the step-by-step forward feeding movement of the strip12a of fastener blanks through. the curving die mechanism 13' and theprogressive curving of' this strip of blanks. into the tube 110, thecompleted ring fasteners 14 will emerge from theforward end of the outerdie 79, as shown in Figs. 1 and 5. The tube of completed ring fastenerswill move along and be supported by'the rod extension 78b ofthe innerdie 78 from which the completed ring fasteners can be removedindividually'or in groups, a: may be desired.

'Fig'. 23 of the'drawings shows a modified form of.apparatus forproducing the pronged ringfasteners' 14 in two parallel groups. In thisimproved apparatus a curving die mechanism 136 is shown having a pair.of outer die'me'mbers 137 and 138 which are reciprocable in aside-by-side relation in a guidebox 139. This curving die mechanism isalso provided with two axially extending inner die members or mandrels1-40 and 141 disposed in the guidebox 139'and with which the outer diemembers 137' and 138 cooperate in the same mannerv and for the samepurpose as the outer die 79 and the mandrel 78 of the curving diemechanism 13 described above.

The recipr'csable outer die members. 137 and 138 cooperate with theirrespective mandrels' 140 and 141 in definingprogressivelyconvergingfdiepassages through which two strips of fastener blanks 142and 143 are advanced in the. same manner as described above for thestrip of blanks 12a. The discharge ends of these die passages aredefined by substantially cylindrical .die tubes 144 and145 mounted inthe outer die members 137 and 14 138 and. disposed in surrounding.relation to stem. extensions'of the mandrels 140'and'141.

Reciprocating movement is imparted to the outer die members 137 and138-b'y mechanism similar to the above described mechanism- 18 and'whichincludes" a rockshaft 148 andlevers 149' and 150 carriedby the rockshaftand connected with the diemembers 137 and 138 by thrust links 151 and152'. The die members 137 and 138 are connected into a unitary assemblyby connectingmeans which includes a pair ofupper and lower splice plates153 applied to the forward end portions of-these die members.

The strips of blanks 142' and 143 are supplied-to the curving diemechanism136'by a shearing die mechanism 10 similar to that alreadydescribed above. The two strips of blanks 142 and 143 are produced'bythe shearing die mechanism 10 by operation thereof on .'two parallelstock strips which are supplied thereto by a feed mechanism similar tothe feed mechanism 15 above described. The two stock strips thussuppliedcan be individual strips withdrawn from separate rolls of stockmaterial or can be a single widestrip of sheet metal" stock whichisrsplit longitudinally by a suitable slitting device, such. as arotatable shearing disk cooperating with abacking roll (not shown), bywhich the-single wide strip is splitinto two parallel individual stockstrips during the feedin movement supplied by the feed mechanism 15. 1

With respect to the die tubes 144 and 145 of the curving die mechanism136, it should be explained that these. die tubes accomplish a shapingand sizing of the transversely curved'strips 142 and 143 into tubes ofcompleted fastener blankssimilar to the function performed. by thecooper.-

ating rolls 112'and 113 ofthe curving die mechanism 13.. If desired,rolls similar to. the rolls. 112 and 113 could be'used in the modifiedcurving die mechanism 136'in place of thedie tubes 144.and 145and,.conversely, atdie tube similarrto one'ofthe' die tubes 144' and 145couldbe used in the'cu'rving die mechanism 13 in place of the.cooperatingrolls 112 and 113.. y

From the accompanying drawings and the foregoing detailed description itwill now'be readily understood that thisinvention'provides novelapparatus by which pronged ring'fasteners can" be produced'rapidly andeconomically and of'a desired uniform characteristic from sheet metal instrip form.

I Although the novel apparatus of the presentinvention has beenillustrated and described herein to a somewhat detailed extent it willbe understood, of course, thatthe invention is not to be regarded as.being limited. corre: spondingly in scope-but'includes all changes andmodifications coming within'the'terms of the claims hereof.

Having thus described my invention, I claim:

1.' In apparatus for producingiring-s'haped articlesfrom a strip ofsheet metal stock, a support, a shearing die mechanism mounted on saidsupport and comprising co.- operating shearing'die members operable tosever fastener blanks in succession from .the leading end of. the stockstrip, guide means onsaid support and located relative to said shearingdie mechanism to receive said blanks directly therefrom and comprisingspaced-apart guide-v surfaces defining guide passage means extending inthe direction of the axis of said stock strip and efiective .formaintaining said'blanks in a series relation with the adjacent edges ofadjacent blanks in abutting engagement so as to constitute a strip ofsaid blanks, feeding means mounted on said support and associatedwithsaid shearing die mechanism and operable to intermittently advance saidstock strip into. said shearing die mechanism and to also intermittentlyadvance said strip of blanks in the same direction and aheadofi saidstockstrip by feeding movement. transmitted through. the latter, and acurling die mechanism mounted on said support and having a formingmeanszreciprocably movable along'said strip of blanks andoperable onthe-latter byirnpingement thereagainstduring'the intervals whensaidvstrip of blanks is relatively stationary to curl said strip of blankstransversely thereof for forming said blanks into ring fasteners atsubstantially the same rate that said blanks are being produced by saidshearing die mechanism, said guide passage means being defined at leastin part by said curling die mechanism.

2. In apparatus for producing pronged ring fasteners from a strip ofsheet metal stock, a support, a shearing die mechanism mounted on saidsupport and comprising cooperating shearing die members operable tosever pronged fastener blanks in succession from the leading end of thestock strip including means for shearing the stock strip on an irregulartransverse line corresponding with the prong profile of a plandevelopment of the fastener, guide means located relative to saidshearing die mechanism to receive said blanks directly therefrom anddefining guide passage means extending in the direction of the axis ofsaid stock strip and effective for maintaining said blanks in a seriesrelation with the prongs of adjacent blanks in interfitting engagementso as to constitute a strip of said blanks, feeding means associatedwith said shearing die mechanism and operable to advance said stockstrip and said strip of blanks with an intermittent movement, saidfeeding means being effective to push said stock strip into saidshearing die mechanism and to also cause said intermittent advancemovement of said strip of blanks by feeding movement transmitted to thelatter through said stock strip, and other die mechanism mounted on saidsupport to receive said strip of blanks directly from said guide meansand having a forming means reciprocably movable along said strip ofblanks and operable thereon by impingement to progressively impart ashaping force to said strip of blanks during the rest intervals betweensuccessive feeding movements for curling the strip of blankstransversely and forming said blanks into ring fasteners.

3. In apparatus for producing pronged ring fasteners from a strip ofsheet metal stock, die mechanism operable to sever relatively narrowdeeply serrated pronged fastener blanks in succession from the leadingend of the stock strip including means for shearing the stock strip onan irregular transverse line at relatively closely spaced intervals andcorresponding with the deeply serrated prong profile of a plandevelopment of the fastener, means for maintaining said blanks in atransversely extending position in a longitudinalseries with the prongsof adjacent blanks in interfitting engagement so as to constitute astrip of said blanks, feeding means operable to advance said stock stripand said strip of blanks with an intermittent movement, said feedingmeans being effective to push said stock strip into the first-mentioneddie mechanism and to also cause said intermittent advance movement ofsaid strip of blanks by feeding movement transmitted to the latterthrough said stock strip, and other die mechanism operable toprogressively impart a shaping force to said strip of blanks during therest intervals between successive feeding movements for curling thestrip of blanks transversely and forming said blanks into ringfasteners, said other die mechanism comprising a tapered hollow diemember reciprocably movable along said strip of blanks.

4. In apparatus for producing ring-shaped articles, a pair of diemembers having'cooperating shearing edges adapted to sever relativelynarrow blanks in succession from the leading end of a strip of sheetmetal stock, means for maintaining said blanks in a transverselyextending position in a longitudinal series with the adjacent edges ofadjacent blanks in abutting engagement so as to constitute a strip ofsaid blanks, a third die member'having internal wall means definingatransversely concave channel recess tapering convergently fromarelatively wide inlet opening at one end thereof to a substantiallyannularly closed delivery opening at the other end, means mounting saidthird die member for reciprocation axially of said channel recess withsaid inlet opening located to receive said strip of blanks, feedingmeans intermittently operable to supply said strip of stock to said pairof die members and to advance said strip of blanks through said channelrecess, means for supporting said strip of blanks in said channelrecess, and means adapted to produce said reciprocation of the third diemember for causing said internal Wall means thereof to Wedgingly impingesaid strip of blanks and progressively shape said blanks to ring form.

5. In apparatus for producing pronged ring fasteners of the characterdescribed, a pair of die members having cooperating relatively deeplyserrated shearing edges adapted to sever relatively narrow deeplyserrated prongedged fastener blanks in succession from the leading endof a strip of sheet metal stock, means for maintaining said blanks in atransversely extending position in a longi tudinal series with theprongs of adjacent blanks in interfitting engagement so as to constitutea strip of said blanks, a third die member having internal wall meansdefining a transversely concave channel recess tapering convergentlyfrom a relatively wide inlet opening at one end thereof to asubstantially annularly closed delivery opening at the other end, meansmounting said third die member for reciprocation axially of said channelrecess with said inlet opening located to receive said strip of blanks,feeding means intermittently operable to supply said strip of stock tosaid pair of die members and to advance said strip of blanks throughsaid channel recess, means for supporting said strip of blanks in saidchannel recess, means operable to produce said reciprocation of thethird die member for causing said internal wall means thereof wedginglyimpinge said strip of blanks and progressively shape said blanks toannular contour, and cooperating die rolls defining a pass located toreceive the contoured blanks from the channel recess of said third diemember, said die rolls being effective on said contoured blanks tocomplete the shaping thereof to substantially closed ring form.

6. In apparatus for producing pronged ring fasteners of the characterdescribed, a pair of die members having cooperating relatively deeplyserrated shearing edges adapted to sever relatively narrow deeplyserrated prongedged fastener blanks in succession from the leading endof a strip of sheet metal stock, means for maintaining said blanks in atransversely extending position in a longitudinal series with the prongsof adjacent blanks in interfitting engagement so as to constitute astrip of said blanks, a third die member having internal wall meansdefining a transversely concave channel recess tapering convergentlyfrom a relatively wide inlet opening at one end thereof to asubstantially annularly closed delivery opening at the other end, meansmounting said third die member for reciprocation axially of said channelrecess with said inlet opening located to receive said strip of blanks,feeding means intermittently operable to supply said strip of stock tosaid pair of die members and to intermittently advance said strip ofblanks through said channel recess, means for supporting said strip ofblanks in said channel recess, means intermittently operable to producesaid reciprocation of the third die member for causing said internalWall means thereof to Wedgingly impinge said strip of blanks during theintervals when the latter is relatively stationary and therebyprogressively shape said blanks to annular contour, cooperating dierolls defining a pass located to receive the contoured blanks from thechannel recess of said third die member, said die rolls being effectiveon said contoured blanks to complete the shaping thereof tosubstantially closed ring form, and means .mounting said die rolls onsaid third die member for translatory movement during the reciprocationof the latter.

7. In apparatus for producing pronged ring fasteners of the characterdescribed, a pair of die members having cooperating relatively deeplyserrated shearing edges adapted to sever relatively narrow deeplyserrated prongedged fastener blanks in succesion from the leading end ofa strip of sheet metal stock, means for maintaining said 17 blanks in atransversely extending position in a longitudinal series with the prongsof adjacent blanks in interfitting engagement so as to constitute astrip of said blanks, a third die member having internal wall meansdefining a transversely concave channel recess tapering convergentlyfrom a relatively wide inlet opening at one end thereof to asubstantially annularly closed delivery opening at the other end, meansmounting said third die member for reciprocation axially of said channelrecess with said inlet opening located to receive said strip of blanksfrom said pair of die members, feeding means operable to intermittentlyadvance said strip of stock to said pair of die members and to alsointermittently advance 1 said strip of blanks through said channelrecess with rest intervals between the advance movements, means forsupporting said strip of blanks in said channel recess, means adapted toproduce said reciprocation of the third die member for causing saidinternal wall means thereof to wedgingly impinge said strip of blanksduring said rest intervals and progressively shape said blanks to ringform, and holding means effective on said strip of blanks during saidrest intervals for holding said blanks against backward movement.

8. In apparatus for producing pronged ring fasteners of the characterdescribed, a pair of die members having cooperating serrated shearingedges adapted to shear transversely extending prong-edged fastenerblanks in succession from the leading end of a strip of sheet metalstock and to leave said blanks in a series relation with the prongs ofadjacent blanks in meshed engagement to constitute a strip of blanks, asecond pair of die members comprising a pair of tapered coaxially nestedrelatively reciprocable cooperating convex and concave die membersdefining therebetween a transversely concave work channel of across-sectional shape varying progressively from a relatively wide inletopening at one end thereof to a substantially annularly closed deliveryopening at the other end, means mounting said second pair of die memberswith said inlet opening located to receive said strip of blanks from thefirst pair of die members, feeding means intermittently operable tosupply the strip stock to said first pair of die members and to advancesaid strip of blanks through said work channel, and means operable toproduce the relative reciprocation of said second pair of die membersfor causing the same to progressively shape said blanks therebetween toring form during their movement through said work channel.

9. In apparatus for producing pronged ring fasteners of the characterdescribed, a support, a first pair of die members having cooperatingserrated shearing edges adapted to sever transversely extendingprong-edged fastener blanks in succession from the leading end of astrip of sheet metal stock and comprising a lower stake die member andan upper punch die member reciprocable relative thereto, means foractuating said punch die member, means on said support defining aguideway, a second pair of die members comprising tapered coaxiallynested cooperating convex and concave inner and outer die membersdefining therebetween a transversely concave work channel varyingprogressively in cross-sectional shape from a relatively wide inletopening at one end to a substantially annularly closed delivery openingat its other end, said second pair of die members being disposed in saidguideway with said inlet opening located to receive said blanks from thefirst pair of die members, feeding means intermittently operable tosupply the strip stock to the first pair of die members and to cause aseries of said blanks to move through said work channel from said inletopening to said outlet opening, means mounting said inner die member insubstantially fixed relation on said support, said outer die memberbeing reciprocable in said guideway for opening and closing movementsrelative to said inner die member for progressively bending said'blanks18 around the latter, and means operable to cause the reciprocation ofsaid outer die member.

10. In apparatus for producing pronged ring fasteners of the characterdescribed, a support, a first pair of die members having cooperatingserrated shearing edges adapted to sever transversely extendingprong-edged fastener blanks in succession from the leading end of astrip of sheet metal stock and comprising a lower stake die member andan upper punch die member reciprocable relative thereto, means foractuating said punch die member, means on said support defining aguideway, a second pair of die members comprising tapered coaxiallynested cooperating convex and concave inner and outer die membersdefining therebetween a transversely concave work channel varyingprogressively in cross-sectional shape from a relatively wide inletopening at one end to a substantially annularly closed delivery openingat its other end, said second pair of die members being disposed in saidguideway with said inlet opening located to receive said blanks from thefirst pair of die members, feeding means intermittently operable tosupply the strip stock to the first pair of 'die members and to cause aseries of said blanks to move through said work channel from said inletopening to said outlet opening, means mounting said inner die member insubstantially fixed relation on said support, said outer die memberbeing reciprocable in said guideway for opening and closing movementsrelative to said inner die member for progressively bending said blanksaround the latter, means operable to cause the reciprocation of saidouter die member, and a pair of cooperating die rolls connected withsaid outer die member for movement therewith and located adjacent saidoutlet opening, said die rolls being effective on said blanks tocomplete the transverse bending thereof to substantially ring form.

11. In apparatus for forming edge-abutting blanks into ring-shapedarticles, a die member having internal wall means defining atransversely concave longitudinal die passage tapering convergently froma relatively wide inlet opening at one end thereof to a substantiallyannularly closed delivery opening at the other end thereof, means forsupporting a series of said blanks in said die passage with theindividual blanks in transversely extending relation to the axis of saiddie passage and with the blanks of the series confined in asubstantially co-planar relation, means for causing said series totraverse said die passage from said inlet opening to said deliveryopening with intermittent forward movement, means mounting said diemember for reciprocating movements axially of said series, and meansadapted to produce said reciprocating movements for causing saidinternal wall means to impinge against said blanks during the intervalswhen said series is relatively stationary to thereby progressively shapethe blanks to ring form.

12. In apparatus for forming prong-edged blanks into pronged ringfasteners, a die member having internal wall means defining atransversely concave longitudinal die passage tapering convergently froma relatively wide inlet opening at one end thereof to a substantiallyannularly closed delivery opening at the other end thereof, means forsupporting a series of said blanks in said die passage with theindividual blanks in transversely extending relation to the axis of saiddie passage, means for causing said series to traverse said die passagefrom said inlet opening to said delivery opening with an intermittentforward movement and substantially preventing backward movementof saidblanks during the rest intervals between the intermittent forwardmovements, means mounting said die member for reciprocating movementsaxially of said series, and means adapted to produce said reciprocatingmovements 'in timed relation to said intermittent forward movement forcausing said internal wall means to im pinge against said blanks duringsaid rest intervals and progressively shape the blanks to ring form.

13. In apparatus for forming prong-edged blanks into pronged ringfasteners, a die member having internal wall means defining atransversely concave longitudinal die passage tapering convergently froma relatively wide inlet opening at one end thereof to a substantiallyannularly closed delivery opening at the other end thereof, means forsupplying a strip comprising a series of said blanks in transverselyextending relation with adjacent blanks having their prongs ininterfitting engagement and causing said strip to move through said diepassage from said inlet opening to said delivery opening withintermittent forward movement, means for supporting said strip in saiddie passage with the blanks of the strip confined in a substantiallyco-planar relation, means mounting said die member for reciprocatingmovements longitudinally of said strip,

means for preventing backward movement of said strip, and means adaptedto produce said reciprocating movements for causing said internal wallmeans to impinge against and deflect side portions of said strip duringthe intervals when said strip is relatively stationary to therebyprogressively shape said blanks to ring form.

14. In apparatus for forming prongedged blanks into pronged ringfasteners, a die member having internal wall means defining atransversely concave longitudinal die passage tapering convergently froma relatively wide inlet opening at one end thereof to a substantiallyannularly closed delivery opening at the other end thereof, means forsupplying a strip comprising a series of said blanks in transverselyextending relation with adjacent blanks having their prongs ininterfitting engagement and causing said strip to move through said diepassage from said inlet opening to said delivery opening withintermittent forward movement, means for supporting said strip in saiddie passage with the blanks of the strip confined in a substantiallyco-planar relation, means mounting said die member for reciprocatingmovements longitudinally of said strip, and means adapted to producesaid reciprocating movements for causing said internal wall means toimpinge against and deflect side portions of said strip during theintervals when said strip is relatively stationary to therebyprogressively shape said blanks to ring form, the taper angle of saidinternal wall means having a relation to the thickness of the sheetmetal of said blanks such that the prongs of adjacent blanks of saidstrip will remain in said interfitting engagement during the progressiveshaping of the blanks to ring form.

15. In apparatus for forming prong-edged blanks into pronged ringfasteners, a die member having internal Wall means defining atransversely concave longitudinal die passage tapering convergently froma relatively Wide inlet opening at one end thereof to a substantiallyannularly closed delivery opening at the other end thereof, means forsupplying a strip comprising a series of said blanks in transverselyextending relation with adjacent blanks having their prongs ininterfitting engagement and causing said strip to move through said diepassage from said inlet opening to said delivery opening with anintermittent forward movement and substantially preventing backwardmovement of said strip during the rest intervals between theintermittent forward movements, means for supporting said strip in saiddie passage, means mounting said die member for reciprocatingwork-stroke and retracting movements longitudinally of said strip, andmeans for producing said reciprocating movements in timed relation tosaid intermittent forward movement such that said work-stroke movementscause impingement of said internalwall means against the sides of saidstrip during said rest intervals for progressively shaping said blanksto ring form and said retracting movements take place during saidforward movements of the strip.

16. Apparatus for forming sheet metal blanks into ringshaped articlescomprising, an outer die member having a convergently tapered diepassage therein, a convergently tapered mandrel disposed in said diepassage in substantial-ly coaxial relation thereto, said outer diemember and said mandrel defining therebetween a transversely concavework space of progressively varying cross-sectional shape adapted to betraversed by a series of said blanks and including a substantiallytubular delivery portion, means for causing said series of blanks totraverse said work space in a direction toward said tubular deliveryportion with intermittent forward movement, said blanks being confinedin said work space in a substantially co-planar relation, meanssupporting said outer die member for reciprocation longitudinally ofsaid die passage, and means for producing reciprocation of said outerdie memher to cause the same to impinge and shape said blanks aroundsaid mandrel during the intervals when said series is relativelystationary.

17. Apparatus for forming prong-edged blanks into pronged ring fastenerscomprising, an outer die member having a convergently tapered diepassage therein, a convergently tapered mandrel die member disposed insaid die passage in substantially coaxial relation thereto, said outerdie member and said mandrel die member defining therebetween atransversely concave Work space of progressively varying crosssectionalshape adapted to be traversed by a series of said blanks in transverselyextending relation for the progressive bending of said blanks tosubstantially ring shape and including a delivery opening, meansmounting said die members such that one die member is reciprocablymovable relative to the other and axially of said passage for causingsaid progressive bending of the blanks, means for causing said blanks tobe advanced intermittently in said work space and to be dischargedthrough said delivery opening, said blanks being confined in said workspace in a substantially co-planar relation, and means operable toproduce the reciprocable movement of said one die member, a pair ofcooperating grooved die rolls located substantially at said deliveryopening for the passage of the ring shaped blanks therebetween, andmeans connecting said die rolls with said one die member for movementtherewith.

18. Apparatus for forming prong-edged blanks into pronged ring fastenerscomprising, an outer die member having a convergently tapered channelrecess therein, a convergently tapered mandrel disposed in said recessin substantially coaxial relation thereto, said outer die member andsaid mandrel defining therebetween a transversely concave work space ofprogressively varying cross-sectional shape adapted to be traversed by aseries of said blanks in transversely extending relation for the progressive bending of said blanks to substantially ring shape and including asubstantially tubular delivery portion, means for causing said series totraverse said work space in a direction toward said tubular deliveryportion and with intermittent forward movement, means mounting saidouter die member for reciprocation relative to said mandrel and alongsaid channel recess for causing said progressive bending of said blanksduring the intervals when said series is relatively stationary, saidblanks being confined in said work space in a substantially co-planarrelation, and means for producing said reciprocation of said outer diemember, said mandrel having a stem portion extending substantiallycoaxially in said tubular delivery portion.

19. Apparatus as defined in claim 18 in which said stem portion of themandrel projects from said tubular delivery portion and forms a supportfor the completed pronged ringfas'tencrs.

20. In apparatus for forming sheet metal blanks into ring-shapedarticles, a support having a longitudinal guideway therein, a pair oftapered coaxially nested cooperating inner and outer convex and concavedie mem bers extending longitudinally in said guideway and definingtherebetween a transversely concave work channel varying progressivelyin cross-sectional shape from a relatively wide inlet opening at one endto a substantially mounting said inner die member in substantially fixedrelation on said support, the blanks of said strip being confined insaid work channel in a substantially co-planar relation, said outer diemember being reciprocable in said guideway and along said work channelfor opening and closing movements relative to said inner die member forprogressively bending longitudinal edge portions of said strip aroundsaid inner die member during the intervals when said strip is relativelystationary to convert said blanks into pronged ring fasteners, and meansoperable to cause such reciprocation of said outer die member.

21. In apparatus for forming sheet metal blanks into ring-shapedarticles, a bed, a hollow die box on said bed and having walls defininga guideway, an outer die member having a transversely concavelongitudinal recess therein tapering convergingly to a substantiallyannularly closed delivery opening at one end thereof, a convergentlytapered mandrel extending longitudinally in said recess, meansconnecting said mandrel with said die box for mounting the mandrel insaid recess, said outer die member and mandrel being spaced apart anddefining therebetween a transversely concave work space of progressivelyvarying cross-sectional shape leading to said delivery opening andadapted to be traversed by said blanks for the progressive bendingthereof to substantially ring shape, means for intermittently advancingsaid blanks in said work space, said outer die member being reciprocablein said guideway and along said recess so as to have successive closingmovements relative to said mandrel for impinging and shaping said blanksaround the latter during the intervals when said blanks are relativelystationary, and

22 means for producing said closing movements of said outer die member.

22. In apparatus for producing prong-edged fastener blanks from a stripof sheet metal stock, a pair of punch and stake die members havingcooperating deeply serrated shearing edges adapted to sever transverselyextending prong-edged blanks in succession from the leading end of saidstrip such that during each such shearing operation one row of prongs isformed on the fastener blank being severed from the strip and anotherrow of prongs is left on the leading end of the strip for the nextsucceeding blank, means for actuating said punch die member forproducing the shearing cooperation with said stake die member, theprong-forming serrations of said punch die member having dependingportions at the apices thereof for deflecting the ends of the prongs ofthe blank being severed out of the plane of such blank, and a row ofdepending lugs on said punch die member located to engage the previouslyformed prongs of said strip and deflect the ends thereof out of theplane of the strip during said shearing operation.

References Cited in the file of this patent UNITED STATES PATENTS224,382 Blake Feb. 10, 1880 639,513 Bristol Dec. 19, 1899 1,290,555Heppes Jan. 7, 1919 2,148,248 Swangren Feb. 21, 1939 2,222,842 HumphreyNov. 26, 1940 2,267,873 Place Dec. 30, 1941 2,444,463 Nordquist July 6,1948 FOREIGN PATENTS 20,907 Great Britain Dec. 23, 1890

